Lifting-jack.



v H'. v. MILLER.

LIFTING JACK.

APPLICATION FILED NOV. 10, 1909.

2 SHEETS-SHEET l.

Patented May 28, 1912.

L WM COLUMBIA PLANOGRAPH 00.,WASHXNGTON. D. c.

H. V. MILLER.

LIPTING JACK.

APPLICATION FILED NOV.10, 1909.

Patented May 28; 1912.

animator 3 SHEETS-SHEET 2.

UNIT

HUSON V. MILLER, OF KALAMAZOO, MICHIGAN.

LIFTIN' G-J'ACK.

To all whom it may concern:

Be it known that I, HUsoN V. MILLER, a citizen of the United States, residing at the city of Kalamazoo, county of Kalamazoo, and State of Michigan, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a speci fication.

This invention relates to improvements in lifting-jacks.

The main objects of this invention are to provide an improved lifting jack of the reversible type, that is, a jack adapted for both the raising and lowering of an object. Second, to provide an improved lifting jack which may be operated in any position. Third, to provide an improved lifting jack which is very simple and economical in structure, and one in which the parts may be quickly and easily assembled, and adjusted to adapt the same for raising or lowering.

Further objects, and objects relating to structural details will definitely appear from the detailed description to follow.

I accomplish the objects of my invention by the devices and means described in the following specification.

The structure described constitutes one effective embodiment of my invention. Other embodiments would be readily devised by those skilled in the art.

The invention is clearly defined and pointed out in the claims.

A structure constituting an effective and preferred embodiment of the features of my invention is clearly illustrated in the accompanying drawing, forming a part of this specification, in which:

Figure 1 is a detail side elevation of a structure embodying the features of my invention, the side plates 4 being removed, the reversing member being shown in its inoperative position. Fig. 2 is a detail side elevation corresponding to that shown in Fig. 1 with the reversing member in its operative position. Fig. 3 is a detail vertical section taken on a line corresponding to line 33 of Fig. 1. Fig. 4 is a detail vertical section taken on a line corresponding to line 47 4: of Fig. 2, the rack and the pawls being shown in full lines. Fig. 5 is a detail side elevation with the side plate 4. removed, of a modified structure, the same being an adaptation of my improvement to a single acting jack, that is, a jack having a lifting pawl and a holding pawl. Fig. 6

Specification of Letters Patent.

Application filed November 10, 1909.

Patented May 28,1912.

Serial No. 527,203.

is a similar view of a further modification, the modification being in the form of the tripping member.

In the drawing, similar reference characters refer to similar parts throughout the several. views, and the sectional views are taken looking in the direction of the little arrows at the ends of the section lines.

Referring to the drawing, the frame 1 is provided with a suitable way for the rack bar 2. The rack bar 2 is provided with the customary head 3 at its upper end. The frame is preferably provided with a removable side plate 1, the frame having an annular flange 5 to which the plate is se cured by means of suitable screws as 6. then this plate is removed the frame is open so that the mechanism may be placed therein.

The operating lever 7 is mounted upon a suitable pivot 8 arranged transversely of the frame. In the construction shown in Figs. 1 to 1- inclusive, the pawls 9 and 10 are mounted upon the lever, one at each side of its pivot 8 so that as the lever is operated up and down the pawls are alternately raised and lowered. The construction shown in Figs. 1 to 4: inclusive is that generally designated as a double acting jack, while those shown in Figs. 5 and 6 are what is generally designated as a single acting jack.

The pawls are held yieldingly in their engaging positions by means of a spring 13,

the spring being preferably Ushaped and mounted upon the pin 1% on the frame with its arms engaging the projecting pins 15 and 16 on the pawls 9 and 10. This spring, which is in effect two springs, holds the pawls in engagement with the rack bar so that the jack may be operated in any position, as on its side, or inclined. The spring is held in engagement with the pawls by the lug 17 on the frame, see Fig. 1.

To reverse the ack, I provide a reversing member preferably consisting of the pawl engaging portion 18 and the adjusting portion 19 which holds the engaging portion in its engaging position. This pawl-engaging portion is preferably L-shaped in general form, and provided with cam projections 20 and 21 adapted to act alternately on the pawls 9 and 10 as they are alternately raised and lowered by the manipulation of the handle or lever. The engaging portion and the adjusting portion of the releasing member are preferably formed integrally of spring material, a piece of spring wire or rod being satisfactory for the purpose. The reversing member is provided with a loop or eye 22 adapted to receive the pivot 23 so that the reversing member is pivotally supported.

The arm-like adjusting member projects through a slot 2% in the frame and is provided with a button or finger piece 25 by which it may be manipulated to engage it with, or release it from, the catch 26. \Vhen the adjusting member is engaged with this catch the releasing member is in position to act on the pawls, alternately engaging them and shifting them against the tension of the spring 13. The spring tension on the reversing member is greater than that of the spring 13 so that the pawls are actuated against the tension of such spring. In the modified construction shown in Fig. 5, the reversing member is modified in form, the pawl engaging cam 21 being formed so that it is engaged by the pawl 9 as it is lowered, and the pawl 11 is released thereby and held out of engaging position until near the end of the lowering movement of the lever, when it is permitted to engage and the pawl 9 is disengaged.

In the modified construction shown in Fig. 6, the reversing member is further modified in shape, it being provided with an arm 27 having a cam projection 28 thereon adapted to engage the lifting pawl, and an arm 29 having a cam 30 thereon adapted to engage the holding pawl, the arm 29 being also provided with a cam projection 81 adapted to be engaged by the pin on the lifting pawl as the pawl moves upward to position, and, through it acting upon the holding pawl, to release the same.

My improved jack is very simple and economical in structure, and the parts may be readily assembled.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a lifting jack, the combination with a frame, of a rack bar, a pair of alternately acting pawls having laterally-projecting pins thereon, means for holding said pawls yieldingly in engagement with said rack, an L-shaped reversing member, the stem portion of said member being provided with a pivot loop at its upper end and being bent to provide a cam coacting with the pin on one of the pawls, the end of the arm portions of said member being turned upwardly to provide a cam coacting with the pin on the other pawl, one end of said pivot engaging loop being extended into an adjusting arm, said member and its adjusting arm being formed integrally of spring material, a pivot on said frame on which said pivot loop is engaged, and a catch on said frame with which said adjusting arm may be engaged whereby said engaging portion is held in its operative position.

2. In a lifting jack, the combination with a frame, of a rack bar, a pair of alternately acting pawls, means for holding said pawls yieldingly in engagement with said rack, an L-shaped reversing member, the stem portion of said member being provided with apivot loop at its upper end and being bent to provide a cam coacting with one of the pawls, the end of the arm portions of said member being turned upwardly to provide a cam coacting with the other pawl, one end of said pivot engaging loop being extended into an adjusting arm, said member and its adjusting arm being formed integrally of spring material, a pivot on said frame on which said pivot loop is engaged, and a catch on said frame with which said adjusting arm may be engaged whereby said engaging portion is held in its operative position.

3. In a lifting jack, the combination with a frame, of a rack bar, a pair of alternately acting pawls, means for holding said pawls yieldingly in engagement with said rack, a reversing member formed of spring material bent to provide a pivot loop and to provide cams coacting alternately with the pawls, and being extended into an adjusting arm, a pivot on said frame on which said pivot loop is engaged, and a catch on said frame with which said adjusting arm may be engaged whereby said engaging portion is held in its operative position.

In witness whereof, I have hereunto set my hand and seal in the presence of two witnesses.

HUSON V. MILLER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

